Iskanje po katalogu digitalne knjižnice

Opis: Supplier evaluation and selection is essential to any organization, and planning an effective and comprehensive approach to that end seems inevitable. Meanwhile, determining the requisite criteria for evaluating and selecting suppliers is probably one of the most important steps to be taken towards developing an evaluation and selection model in the organization. In this article, first a review of the literature on the criteria and the field of supplier evaluation and selection are provided. These criteria are then placed into proper categories. In order to formulate a supplier evaluation and selection framework for the manufacturing organization under study, the implemented categorization is applied where a list of fifteen attributes and performance criteria is created; where upon it is secured with the help of a designated panel (project team). These features are then screened using Lawshe's method the "social attribute" is removed from the list of fifteen. The remaining 14 other criteria are configured within the SEAP (Suppliers Evaluation based on Attributes and Performances) framework. The framework follows the objective of continually evaluating suppliers, both potential and actual ones through incorporating their performances into their qualification ratings. Based on the proposed framework, suppliers are evaluated on the basis of two types of criteria, - feature (attribute) and performance.
Ključne besede: framework, supplier evaluation, supplier selection, criteria, performance measurement, attributes, Lawshe's method
Objavljeno v DKUM: 22.08.2024; Ogledov: 73; Prenosov: 2
Celotno besedilo (617,06 KB)
Gradivo ima več datotek! Več...

Ključne besede: camera, particle, measurement, silhuette, volume, position
Objavljeno v DKUM: 22.05.2024; Ogledov: 157; Prenosov: 8
Celotno besedilo (3,99 MB)
Gradivo ima več datotek! Več...

Opis: We proposed a method for measuring frequency differences of the order of a few Hz with an experimental error lower than 0.0001% by using two 4 MHz quartz oscillators, the frequencies of which are very close (a few 10 Hz difference) due to the dual mode operation (differential mode with two temperature-compensated signal frequencies or a mode with one signal and one reference frequency). We compared the existing methods for measuring frequency differences with the new method which is based on counting the number of transitions through zero within one beat period of the signal. The measuring procedure requires equal experimental conditions (temperature, pressure, humidity, parasitic impedances etc.) for both quartz oscillators. To ensure equal resonant conditions for oscillation two quartz crystals are needed, which form a temperature pair. The frequencies and resonant conditions of both oscillators must be almost equal, which is achieved by an external inductance or capacitance. In such a way, we minimized all the external effects and ensured highly stable oscillations and high sensitivity of the differential sensors. The counter detects one beat period by an external gate signal former. By using the method of counting transitions through zero within one beat period, we reduced the measuring error by three orders of magnitude, compared to the existing methods.
Ključne besede: small frequency difference measurement, temperature-compensated quartz sensors, differential sensors, quartz oscillators, transitions-through-zero method
Objavljeno v DKUM: 26.03.2024; Ogledov: 357; Prenosov: 246
Celotno besedilo (4,21 MB)
Gradivo ima več datotek! Več...

Opis: This paper deals with the implementation of a measurement system, capable of performing real-time data acquisition and control, and allows the performance analysis of electric drives used for electric vehicle propulsion. For applying the mechanical load on the shaft of the tested motor three different test bench configurations with different power and speed ranges can be used. The main objective of the measurement system is to perform routine performance tests and road simulation tests (in terms of driving cycles) of an electric drive. It provides a research environment for analysis, investigation and study of electric drives and control strategies.
Ključne besede: measurement system, test bench, electric machines, electric vehicles, permanent magnet synchronous motor
Objavljeno v DKUM: 04.12.2023; Ogledov: 383; Prenosov: 23
Celotno besedilo (18,06 MB)
Gradivo ima več datotek! Več...

Opis: The paper presents an efficient way to evaluate and determine the quality of an assembled printed circuit board coming off the production line. A printed circuit board assembly consists of electronic devices soldered to the printed circuit board, which provides the electrical connections. After assembling the printed circuit board, a function test needs to be performed to guarantee the quality of the product. Usually, the assembly lines are equipped with cameras that detect inaccuracies such as missing components. This level of quality assurance is sometimes not enough, and we need to add another degree of precaution. In addition to camera inspections, electronic measurements must be conducted. The process needs to be automated to provide repeatability and speed. The paper evaluates such a device and presents its advantages, disadvantages, and complexity. The device includes an electrical part that performs the measurements, a mechanical part that consists of a housing and a mounting nest, and a program that supervises the process.
Ključne besede: electrical measurement, printed circuit board, testing device, automation, intelligent measuring system
Objavljeno v DKUM: 30.10.2023; Ogledov: 385; Prenosov: 10
Celotno besedilo (2,26 MB)
Gradivo ima več datotek! Več...